JP3069718B2 - Wire dot printer with switchable printing mode - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire dot printer capable of switching print modes.

[0002]

2. Description of the Related Art Conventionally, there is a print head in which a plurality of print wires are electromagnetically driven to form a dot matrix record on a recording medium on a platen via an ink ribbon at an end of the print wire. In recent years, higher printing density has been required, and the number of printing wires has increased along with this. For example, 24 printing wires have been arranged in two rows in a direction substantially perpendicular to the moving direction of the print head. . The tip of each printing wire passes through a predetermined guide hole of the tip guide.

The arrangement of the print wires includes a parallel arrangement in which two wires adjacent to each other in the moving direction of the print head are located at the same level, and a staggered arrangement in which the positions are shifted from each other by a half pitch. Parallel arrangement is for high-speed printing (Dra
FT mode), staggered arrangement is for high density printing (NLQ
(Near Letter Quality) mode)
Suitable for.

The prior art discloses a configuration in which the parallel arrangement and the staggered arrangement can be arbitrarily switched as required, and the vertical pitch of the parallel arrangement can be changed as required.

First, Japanese Patent Publication No. Sho 57-60950 discloses that a wire guide is divided into two parts, and guide holes for guiding half of the print wires are arranged in a line in a vertical direction. A configuration is shown in which the relative positions of the print wires are switched to a parallel arrangement or a staggered arrangement by moving both wire guides relatively vertically.

[0006] Second, as disclosed in Japanese Patent Application Laid-Open No. 1-25345.
In Japanese Patent Application Publication No. 5 (1999) -1995, two wire guides for guiding print wires are laminated, and one wire guide is provided with two parallel vertical grooves, and half of the print wires are fitted into each vertical groove. The other wire guides are provided with inclined grooves having different inclination angles with respect to the horizontal line, corresponding to the respective print wires, and the print wires are staggered by both guides. The inclined groove has a small pitch at one end and a large pitch at the other end, and changes the vertical pitch of the printing wire by relatively moving both wire guides in the horizontal direction. The configuration is shown. The flute guide is embedded in the recess at the tip of the nose.
The horizontal groove guide is horizontal inside the concave part at the tip of the nose.
It is provided movably in a penetrating part penetrated in the direction.

[0007]

In the first prior art, since the wire guide is divided into two, it is necessary to obtain relative positional accuracy between the printing wires guided by each wire guide. It is difficult, and one of them is moved in the vertical direction. Therefore, the dimensional accuracy of the supporting portion is required, and a driving device is required, which increases the cost.

[0008] The above-mentioned second prior art is directed to both vertical and horizontal guides.
Is used to guide the print wire.
The mounting requires high positioning accuracy.
The guide is positioned by the outer shape of this guide.
Swelling. That is, the vertical groove guide and the concave
Section, lateral groove guide and supports it horizontally movable
The fitting accuracy of each of the penetration portions is required to be high.
If the fitting accuracy between the vertical groove guide and the recess is poor,
It is impossible to fix the flute guide to the
Lateral groove guide and penetration to support it horizontally
If the fitting accuracy of the
Horizontal movement is not possible, so good printing wire
Guide cannot be performed, and the print quality deteriorates. in this way,
In the case of positioning using the outer shape of the vertical and horizontal guides, the dimensional accuracy of the supporting portion that supports the wire guide is required, and the component cost increases.

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to switch the relative positions of two rows of printing wires and to change the vertical pitch between printing wires with a simple structure without requiring high dimensional accuracy. It is in.

[0010]

In order to achieve the above object, a wire dot printer according to the present invention is mounted on a carriage, is moved in the width direction of a recording medium, and has a plurality of electromagnetically driven. In a wire dot printer having a print head in which a print wire is aligned and supported by a nose portion of a head frame, a nose portion is provided with first and second tip guides for aligning the tip portions of the print wires in at least two rows. They are provided facing each other in the direction in which the wire is drawn. The first and second tip guides are either one of
Is provided so that it can swing in the plane direction with its one end as the swing center.
At least two long grooves extending in the vertical direction are provided in parallel on the first distal end guide, and a plurality of printing wires penetrate each long groove. A plurality of slidable grooves through which each print wire penetrates are provided in the second tip guide so that the relative position of at least two rows of print wires or the vertical pitch between each print wire can be changed by swinging. It is provided.

One end of the groove of the second end guide is provided at a position for guiding the printing wires in a staggered arrangement and at a large vertical pitch, and the other end is provided at a position in which the printing wires are staggered and having a small vertical pitch. The guide wire is provided at a position to guide the print wire at a gradually smaller vertical pitch from one end to the other end, and the vertical pitch of the print wire is changed by swinging.

The groove of the second tip guide has one end provided at a position for guiding the printing wires in a staggered arrangement at a large vertical pitch, and is provided between the one end and the center thereof. The print wires are provided in positions that guide the print wires in a staggered and gradually smaller vertical pitch, and the other ends are provided in positions that guide the print wires in a parallel configuration and in a smaller vertical pitch. The vertical pitch is changed and the staggered arrangement and the parallel arrangement are switched.

As means for swinging one of the tip guides, a driven tooth profile is provided at the other end of the second tip guide, and has a drive tooth profile that meshes with the driven tooth profile and is swingably supported. A switching lever may be provided, and the second tip guide may be configured to swing by the swing of the switching lever.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a preferred embodiment of the present invention. FIG. 1 shows a front view of a print head 1 formed with wire dots, and FIG. 2 shows a cross section thereof. As shown in FIG. 2, in the print head 1, as an electromagnetic driving device,
An iron core 2, a drive coil 3, a printing lever 4, a return spring 5, and the like are provided. The 24 print wires 6 are fixed to the inner ends of the print levers 4, are attracted to the iron core 2, print when the inner ends of the print levers 4 advance, and retreat by the spring force of the return spring 5. . A head frame 7 is fixed to the front surface of the print head 1, and a print wire 6 penetrates a nose portion 7 a protruding forward from the head frame 7, and a first and second two end guides 8. , 9.

The first tip guide 8 is fixed to the front end of the nose 7a of the head frame 7 to form a fixed guide. That is, as shown in FIG. 3, fixed holes 8a and 8b are provided at both upper and lower ends, and are fixed to the nose portion 7a using fixed shafts 10 and 11 shown in FIG. The first tip guide 8 is provided with two parallel rows of long grooves 8c and 8d extending in a direction (vertical direction) perpendicular to the direction in which the print head 1 moves. Each of the long grooves 8c and 8d has a length through which twelve printing wires 6 penetrate and a sufficient clearance.

The second end guide 9 is located at the rear of the vicinity of the first end guide 8, and has a hole 9a at the lower end as shown in FIG.
The fixed shaft 10 is rotatably penetrated through the hole 9a. Therefore, the second tip guide 9 can swing about the fixed shaft 10 in the plane direction with the swing center as the swing center.
An arc-shaped guide hole 9 b centered on the fixed shaft 10 is provided at the upper end of the second tip guide 9. This guide hole 9
The fixed shaft 11 penetrates through “b”. The second tip guide 9 is provided with a plurality of slidable grooves 9c and 9d through which the printing wires 6 penetrate, and the second tip guide 9 swings to align in two rows. The relative positions of the printing wires 6 and 6 or the vertical pitch between the printing wires can be changed. Note that reference numeral 9e denotes a driven tooth profile described later.

One embodiment of the specific shapes of the grooves 9c and 9d will be described with reference to FIG. Each of the grooves 9c and 9d is arranged in two rows with a length extending substantially in a fan shape from the lower groove to the upper groove, and each groove has a different inclination angle with respect to the horizontal direction. That is, as shown in FIG. 5A, when the printing wires 6 are located in two rows at one end (right end) of the groove in each row, the relative arrangement of the printing wires is staggered and small. The printing wire is guided at a vertical pitch. Also, as shown in FIG. 5B, when the printing wires 6 are located in two rows at the other end (left end) of each row of grooves, the relative arrangement of the printing wires is staggered, and The printing wire is guided at a large vertical pitch. And
Between the one end and the other end, the printing wire is guided so that the printing wire gradually changes from a small vertical pitch to a large vertical pitch. As shown in FIG. Guided at an intermediate vertical pitch.

The means for swinging the second tip guide 9 is as follows.
A projection (not shown) may be provided integrally, and may be manually swung by the projection, or may be swung via the switching lever 12 as shown in FIGS. That is, a driven tooth 9e is provided integrally with the other end of the distal end guide 9, and the switching lever 12 is provided with a driving tooth 12a that meshes with the driven tooth 9e. The central shaft 13 of the driving tooth profile 12a is fixed to the head frame 7, whereby the switching lever 12 is pivotally supported about the central shaft 13.

To position the switching position of the switching lever 12, a click claw 12b is projected from the back surface of the switching lever, and a click claw 12b is formed on the upper surface of the head frame 7.
Form a click 7b that can be selectively engaged. By engaging the two, the switching lever 12 can be switched in a stepwise manner, and the position is kept stable. Further, a stopper 14 is provided upright on the front surface of the head frame 7 to determine the degree of the switching lever 12. Reference numeral 15 denotes an ink ribbon insertion guide.

Next, the operation will be described. First, when printing at the highest density, the switching lever 12 is swung clockwise around the central axis 13 as shown in FIG. 6 to move the second tip guide 9 via the driving tooth profile 12a to the fixed shaft. 10
Swing counterclockwise around. This state is shown in FIG.
In this state, the printing wire 6 is guided by the right ends of the grooves 9c and 9d, and the long groove 8 of the first tip guide 8 is provided.
Guided by c and 8d, they are arranged in two rows. That is,
The two rows of printing wires are arranged in a staggered manner, and the vertical pitch is small. When printing with this arrangement of printing wires,
Since the amount of overlap of dots formed by adjacent print wires is large, high-density printing is achieved, and fine printing comparable to printed characters can be performed.

In order to print a large character even though the printing density is slightly inferior, the switching lever 12 is swung counterclockwise around the central axis 13 and the second tip guide 9 is rotated about the fixed shaft 10. Swing clockwise. As a result, FIG.
As shown in (b), the printing wires 6 are guided by the left ends of the grooves 9c and 9d, and are also guided by the long grooves 8c and 8d of the first tip guide 8, and are aligned in two rows. That is, the two rows of printing wires are arranged in a staggered manner, but the vertical pitch is the largest. When printing is performed with the arrangement of the printing wires, the overlapping amount of the dots formed by the adjacent printing wires becomes the smallest, so that the printing density is reduced, but large characters can be printed.

The printing density and the size of the printing characters can be changed as required. That is, the switching lever 12 is appropriately swung, the second tip guide 9 is swung, and the position of the groove for guiding the print wire 6 is set, for example, at the center shown in FIG. By moving to the position of the intermediate portion, an intermediate print density and an intermediate character size can be obtained, and therefore, they can be arbitrarily set as needed.

In order to switch the printing wire 6 to the parallel arrangement, as shown in FIG. 7, the shapes of the grooves 19c and 19d formed in the second tip guide 19 are changed to the grooves 9 described above.
A slightly different shape is used for c and 9d. That is,
The shape of the grooves 19c, 19d from the left end to the middle is the same as the shape of the grooves 9c, 9d, and the shape from the middle to the right end is slightly gently curved in the groove 19c.
Let's make the curve a little steep. With such a shape,
When the printing wires 6 are guided by the right ends of the grooves 19c and 19d and guided by the long grooves 8c and 8d of the first tip guide 8, when the printing wires 6 are aligned in two rows, the relative positions of the two rows of printing wires are set. Are arranged in parallel, and have a small vertical pitch. In this arrangement of the printing wires 6, by supplying a drive signal for forming each character to each row of printing wires, the printing density is reduced but the printing speed is increased.

The number of print wires is not limited to 24, and is not limited to those arranged in parallel in two rows. For example, the wires may be arranged in a rhombus or arc shape. Also,
In the above embodiment, the example in which the second tip guide 9 is driven to swing is shown, but the first tip guide 8 may be swingable. Further, the long grooves 8c and 8d are not limited to those extending in the vertical direction, and may be inclined and extend. Further, the means for swinging the distal end guide is not limited to the above example, and may be switched using power.

[0025]

As described above, according to the present invention, printing
When switching the wire pitch, the first and second tips
Is realized by swinging one side of the id.
High accuracy mounting by positioning with shaft and hole
Therefore, high position accuracy can be easily realized.
is there. That is , the two tip guides are overlapped in the thickness direction, and one of the guides is swung in the plane direction with one end as the swing center, so that the clearance required for the movement can be small and the relative positional accuracy can be improved. it can. Therefore, during manufacturing
Since high dimensional accuracy is not required, the manufacturing is easy, and the vertical pitch between the printing wires can be changed with a simple configuration . Further, by appropriately setting the shape of the groove, the relative positions of the two rows of printing wires can be switched between the staggered arrangement and the parallel arrangement, and the cost can be reduced. Also, when switching the printing wire,
The drive of one end guide is realized by swinging.
Because, the swinging of the tip guide is also the capacity <br/> easily by switching lever, configuration can be provided easily and inexpensively.

[Brief description of the drawings]

FIG. 1 is a front view of a printer head according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a central part of FIG.

FIG. 3 is an enlarged front view of a first tip guide.

FIG. 4 is an enlarged front view of a second tip guide.

FIGS. 5A, 5B, and 5C are enlarged front views illustrating states of a printing wire guided by a long groove of a first tip guide and a groove of a second tip guide, respectively.

FIG. 6 is a front view showing an example of means for swinging a second tip guide.

FIG. 7 is a partially cut-away enlarged front view showing another example of the second tip guide.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Print head 6 Print wire 7 Head frame 7a Nose part 8 First end guide 8c, 8d Long groove 9, 19 Second end guide 9a Fixed shaft is rotatably penetrated.
Hole 9b Guide hole 9c, 9d, 19c, 19d Groove 9e Followed tooth profile 10, 11 Fixed shaft 12 Switching lever 12a Drive tooth profile

Claims (4)

(57) [Claims] 1. A wire dot having a print head mounted on a carriage, moved in the width direction of a recording medium, and having a plurality of electromagnetically driven print wires aligned and supported by a nose portion of a head frame. In the printer, the nose portion is provided with first and second tip guides for aligning the tip portions of the printing wires in at least two rows, facing each other in the direction in which the printing wires extend . Either one of the 2 tip guides is fixed
And the other side is centered on one end
Provided swingably in direction, the said first tip guide, at least two long grooves extending in the longitudinal direction is provided with in parallel, a plurality of print wires to the respective elongated groove penetrates The second tip guide has a plurality of grooves through which the print wires penetrate and slidable, and the relative positions of the at least two rows of print wires or the vertical positions between the print wires due to the swing. possible wire dot printer switches the print mode, wherein the Ru Oh provided so changeable pitch. 2. The printing device according to claim 1, wherein one end of the groove of the second tip guide is provided at a position for guiding the printing wires in a staggered arrangement at a large vertical pitch, and the other end is formed of the printing wire. Are provided at positions that guide the print wires in a staggered arrangement and at a small vertical pitch, and are provided at positions that guide the print wires at a gradually smaller vertical pitch from the one end to the other end. A wire dot printer that can switch the printing mode to use. 3. The groove according to claim 1, wherein one end of the groove of the second end guide is provided at a position for guiding the printing wires in a staggered arrangement at a large vertical pitch, and a center portion of the groove from the one end. And the other end is provided at a position to guide the printing wires in a parallel arrangement and at a small vertical pitch. A wire dot printer capable of switching the printing mode characterized by the following. 4. The method according to claim 1, wherein
A driven tooth profile is provided at the other end of the second end guide,
A printing lever is provided, which has a driving tooth profile meshing with the driven tooth profile and is swingably supported, and the second tip guide is swingably driven by swinging of the switching lever. Switchable wire dot printer.